1. Division in Anatomy and Developmental Biology, Department of Oral Biology, Research Center for Orofacial Hard Tissue Regeneration, Oral Science Research Center, College of Dentistry, Brain Korea 21 Project for Medical Science, Yonsei Center of Biotechnology, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul, 120-752, Korea; and
2. Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Japan